The present invention relates to an image display apparatus including an input unit such as a keyboard, a computer body and a display unit, and more particularly to an image display apparatus in which a display size, a display position and brightness of a picture in the display unit can be adjusted by the input unit such as the keyboard through the computer body to improve the handling capability. The image display apparatus of the present invention can be used in a work station and an advanced personal computer using a display unit.
At present, in the display units for a computer terminal, the display position and size of the picture and a deflection frequency of a video signal to be displayed are variously different. Accordingly, one display unit for the computer terminal is designed to be able to treat various video signals.
The display unit of this type employs a microcomputer and an LSI memory to provide an optimum picture display for each kind of video signals. Such a display unit in a prior art is disclosed in Japanese Patent Unexamined Publication No. 1-321475, for example.
This conventional display unit is directed to a multi-scan type CRT display unit, which includes a memory in which information relative to display positions and sizes of the picture is stored for each kind of video signals and which is controlled by a microcomputer in that display unit. The information relative to the optimum display position and size of the picture in accordance with an input video signal is read out from the memory and a deflection circuit of the display unit is controlled by the read-out information. Further, when a video signal inputted in the display unit is not known, the memory stores no information relative to the inputted video signal and accordingly adjustment switches disposed on a front panel of the display unit are operated without the intervention of the computer so that information for adjusting the display position and the display size of the picture is inputted. A control circuit such as the microcomputer prepares information for control including deflection and makes adjustment.
In the prior art described above, the display unit is designed to obtain the optimum picture display in accordance with the input video signal, while, in another prior art, a display state is controlled to be switched from the computer body in accordance with the variety of the multi-media. Such a display unit in the prior art is disclosed in Japanese Patent Unexamined Publication No. 2-60193.
This conventional display unit is directed to a CRT display apparatus used in display of an electronic apparatus such as a personal computer and which can switch the number of scanning lines between 200 lines and 400 lines freely and be shared by a television receiver.
More particularly, in the above prior art, the computer body produces a discrimination signal super-posed on an video signal during a blanking period and the display unit switches the deflection frequency on the basis of the discrimination signal.
In the former prior art (Publication No. 1-321475) of the above two prior arts, since the display position and size of the picture are all controlled by the display unit, it is necessary for the operator to separate his fingers from the input unit such as the keyboard connected to the computer body and extend his hands to the adjustment switches of the display unit disposed at a separate location to operate the switches when the adjustment of the display position and size of the picture are required. Accordingly, it is trouble-some in the handling capability.
Further, in the latter prior art (Publication No. 2-60193), the display state is controlled by the input unit such as the keyboard connected to the computer body, while since only the deflection frequency can be switched only by a binary value, there is a problem that only two specific signals can be treated and a sufficient display state required by the user of the computer can not be obtained.
It is a primary object of the present invention to solve the problems in the prior arts by providing an image display apparatus capable of adjusting a display picture by an input unit such as a keyboard near at hand through a computer body without extending the hands to adjustment switches of a display unit and obtaining a display state required by the user exactly.
It is another object of the present invention to improve the operability in a computer system and the handling capability of the image display apparatus.
It is still another object of the present invention to provide an image display apparatus capable of adjusting a display picture from a computer body by using a conventional circuit without the provision of a new circuit.
In order to solve the above problems, according to the present invention, in a general computer system, a computer body comprises addition means for adding a control signal for a display picture to a video signal or a synchronizing signal and a display unit comprises separation means for separating the added control signal and control means for adjusting the display state on the basis of the separated control signal.
Alternatively, the computer body comprises preparation means for preparing the control signal to produce it with a predetermined system and the display unit comprises control means for receiving the control signal to adjust the display state on the basis of the control signal.
Alternatively, the computer body comprises display processing means for producing the prepared image data and the control signal for the display picture in the form of a digital signal to the display unit and the display unit comprises control means for preparing an analog video signal and synchronizing signal from the image data and producing an adjustment signal for adjusting a predetermined location of the display unit on the basis of the control signal.
Alternatively, the computer body comprises modulation means for adding the control signal for the display picture to an AC power supply for operating the computer body and the display unit comprises demodulation means for separating the modulated control signal and control means for adjusting an internal circuit of the display unit by the control signal from the demodulation means to obtain a predetermined display picture.
Further alternatively, the control signal from the input unit such as the keyboard is received by the display unit as it is and the display unit comprises instruction identification means for identifying the control signal relative to the adjustment of the display picture and control means for adjusting the display picture on the basis of a signal from the instruction identification means.
The addition means of the computer body adds the control signal for the display unit to the video signal or the synchronizing signal produced by the computer body when the instruction inputted by the input unit such as the keyboard relates to the adjustment of the display picture of the display unit. In the display unit the separation means takes out the added control signal and the control means adjusts the internal circuit of the display unit in accordance with the control signal to thereby display a predetermined picture.
Alternatively, the preparation means prepares a control signal in accordance with the control signal for the display picture from the input unit such as the keyboard and produces it through an exclusive connection line, and when the control means of the display unit receives the control signal, the control means adjusts a predetermined portion of the internal circuit of the display unit in accordance with the control signal and adjusts the display picture.
Alternatively, the display processing means processes a drawing instruction prepared by a CPU in the computer body to prepare image data for displaying a video signal and prepare a control signal for the display picture, so that the image data and the control signal are produced to the display unit with a predetermined system for transmission and reception of a digital signal. Further, the control means receives the image data and the control signal from the display processing means and prepares the video signal, the synchronizing signal and the adjustment signal for the internal circuit of the display unit.
Alternatively, the modulation means prepares the control signal for the display picture from the information or instruction relative to the adjustment of the display picture and adds the control signal to the AC power supply for the computer body to transmit the control signal. The demodulation means extracts the control signal added by the modulation means. The control means adjusts a predetermined portion of the internal circuit of the display unit on the basis of the control signal from the demodulation means to adjust the display picture.
Further alternatively, the instruction identification means identifies a signal relative to the adjustment of the display picture from signals directly inputted by the input unit such as the keyboard to prepares the control signal for adjustment. The control means adjusts the predetermined portion of the internal circuit of the display unit in accordance with the control signal from the instruction identification means to adjust the display picture.